A novel beam-steerable 3-bit antenna array is presented for millimeter-wave application. The design operates at 28GHz and consists of a tightly stacked aperture feeding antenna with eight reconfigurable quantized phases which can effectively steer the beam from +50° to-50°. Three different configurations were fabricated and tested. The measured antenna is in good agreement with the simulation result. The measured broadside gain was 13.44 dBi with the gain threshold of 10dBi within the steering range (viz. 100°).